Research On Fault-tolerant Control Strategy Of Key Sensors For Direct Drive In-wheel Electric Vehicle

With the national policy support for the new energy vehicle industry,more and more manufacturers begin to pay attention to the independent intellectual property development of the automobile industry.As a cutting-edge driving form of electric vehicle,direct drive in-wheel electric vehicle has gradually become the development direction of electric vehicle with its advantages of compact structure,high transmission efficiency and flexible operation.Aiming at the problem that the fault of speed sensor and current sensor of direct drive in-wheel electric vehicle will affect the handling safety of the whole vehicle,a speed sensor fault-tolerant control strategy based on flux observer and a current sensor fault-tolerant control strategy based on phase current reconstruction are proposed.A three-degree-of-freedom vehicle dynamics model was established to analyze the influence of speed sensor fault on the vehicle dynamic performance.A state-switching method based on power angle compensation was designed to obtain a smooth torque transition.For the fault of current sensor,the reconstructed phase current was used to replace the measured current to ensure the stable operation of the driving system,and the resonance link is added to the PI controller to eliminate the influence of measurement error.The effectiveness of fault-tolerant control strategy was verified by Matlab-Car Sim co-simulation.The results show that the proposed control strategy can improve vehicle driving performance and yaw stability while sensors are fault.